Antibiotics are widely used in medicine for the treatment of infections caused by susceptible microbiological organisms. Many of these drugs have toxic side effects and/or require increased doses for treatment of certain infections. Therefore, there exists the need to develop a system to improve the biological activity of anti-microbials. The applicants have discovered that the biological activity of a bioactive agent may be increased by complexation with cyclodextrin. The cyclodextrin-complexed bioactive agent may be administered to treat infection caused by a susceptible microorganism.
The present invention relates to the discovery that complexation of a bioactive agent to a complexing agent increases the biological activity of the bioactive agent. Thus, the present invention provides methods of increasing the biological activity of a bioactive agent by complexing the bioactive agent to a complexing agent. In certain preferred embodiments, the bioactive agent is an antibiotic and the complexing agent is a cyclodextrin. In particularly preferred embodiments, a hydrophobic antibiotic, such as chlorhexidine, tetracycline, tobramycin, or gentamicin, is complexed with a cyclodextrin, such as methyl-xcex2-cyclodextrin or hydroxypropyl-xcex2-cyclodextrin, to increase the ability of the antibiotic to inhibit microbial growth. Naturally occurring cyclodextrins as well as modified naturally occurring cyclodextrins and chemically modified cyclodextrins may be used in the inventive method.
The present invention further provides methods of treating a microbial infection in an animal by administering to the animal an effective amount of an antibiotic having increased biological activity. According to the teachings of the invention, the biological activity of the antibiotic is increased by complexing it with a cyclodextrin. Those skilled in the art will appreciate that the inventive methods may be extended to other diseases or disorders that are treatable with the appropriate bioactive agent, the activity of which has been increased according to the invention.